Method and means for utilizing helical armor rods



Dec. 29, 1964 1-. F. PETERSON 3,163,706

METHOD AND MEANS FOR UTILIZING HELICAL ARMOR RODS 2 Sheets-Sheet 1 Original Filed April 27. 1949 INVENTOR. T/zoW/Tekraafz,

METHOD AND MEANS FOR UTILIZING HELICAL ARMOR RODS Original Filed April 27, 1949 Dec. 29, 1964 T. F. PETERSON 2 Sheets-Sheet 2 INVENTOR 3Y7 72002661 Fife/1707a @ww M M lfiwi 9M United States Patent OfiFice 3,163,706 Patented Dec. 29, 1964 3,163,706 METHOD AND MEANSFOR UTILIZING HELICAL ARMOR RODS Thomas F. Peterson, Shaker Heights, Ohio, assignor to Preformed Line Products Company, Cleveland, Ohio, a corporation of Ohio Original application Apr. 27, 1949, Ser. No. 89,986, now Patent No. 3,007,243, dated Nov. 7, 1961. Divided and this application Aug. 2, 1960, Ser. No. 47,107

Claims. (Cl. 174-42) This case is a division of my application Serial No. 89,986, filed April 27, 1949, for Method and Means for Utilizing Helical Armor Rods, now Patent No. 3,007,243.

The invention herein disclosed and claimed relates to the reinforcement, hanging, tapping, clamping, gripping and dead-ending of overhead electrical transmission lines. More specifically, the invention is concerned with the adaptation and utilization for such purposes of helically preformed armor rods, like those shown in and covered by my patents, No. 2,275,019, No. 2,587,521, and No. 2,761,273, and my copending applications, Serial No. 698,312, filed September 20, 1946, now Patent No. 3,007,- 300, and Serial No. 2,200, filed January 14, 1948, now abandoned.

As mentioned in my previous patents and applications, armor rods comprising helically preformed metal or plastic bodies shaped to an internal helical diameter and angle of lay, or pitch angle, to be applied to overhead transmission lines and similar bodies from the side of the latter, are so applied usually by dividing a set of armor rods into two groups and by arranging the groups upon each side of the transmission line and twisting the opposite ends in opposite directions suitable to the hand of the helix, until the rods come into place about the conductor. This may be done manually or with the use of tools, and the conductor may be completely enclosed by an appropriate number of armor rods, or partially enclosed by the attachment of but one or more for this purpose. These rods, being formed from fairly rigid stock to a helical diameter the same as or slightly less than the outside diameter of the suspended line of association, tightly grip the latter when in place, and resist displacement in any direction of the line save by untwisting.

Previously, it has been customary to apply such armor at points of suspension of overhead transmission lines for the purpose of reinforcing the lines adjacent the connections to minimize bending stresses, while at the same time insuring that the lines are securely anchored against longitudinal slippage. This protects the lines against damage by chafing at the supports, and against fatigue stresses, which localize at such points. The fastenings to the supports have usually been efiected by the conventional type of clamps or ties known to the industry.

It is the first object of the invention to utilize armor rods in addition to their normal functions for the attachment of hanger fixtures or taps to electrical conductors in such a Way that extraneous fittings, clamps, ties, etc., are completely eliminated, and so that a more efficient, economical type of hanger or tap is provided. i

It is a corollary object to provide fastenings of this kind for electrical conductors which have the simplest possible mechanical characteristics, and which afford greatly improved electrical properties in the avoidance of corona losses throughout the installation, and in effecting stable, low-resistance electrical joints.

It is another object to provide electrical conductor fittings of the kind described which may be attached in the field with substantially the same ease of application that preformed armor rods are themselves applied, and further, which will afford a degree of permanence against displacement'such as characterizes the more elaborate,

expensive, and ineificient fittings currently provided for this purpose.

It is a related object to provide fittings for electrical conductors and other suspended lines that act as efiicient vibrational dampers.

In the accompanying drawings, FIGURES 1 and 2 are side elevational and end views, respectively, of a single length of a helically preformed armor rod made to perform the needs of the invention herein contained, and as appears in my preceding patents and applications above identified.

FIGURE 3 is a side elevational view of the method of armoring an electrical conductor by the manual application of helically preformed armor rods, which are divided into two groups arranged upon opposite sides of the conductor and simultaneously twisted in opposite directions.

FIGURE 4 represents a side elevational view of the wrapping process, the initiation of which is illustrated in FIGURE 3, showing the rods nearly completely in position to enclose the conductor. FIGURES 5 and 6 are side'and end views, respectively, of the installation of armor rods in place upon a conductor.

FIGURE 7 is a side elevational view of one form of hanger or tap fitting for use in connection with the present invention.

FIGURE 8 is a sectional view taken along line 88 of FIGURE 7, while FIGURE 9 is a view corresponding to FIGURE 8 showing the fitting in open position to embrace a conductor.

FIGURE 10 is a plan view of FIGURE 7, while FIG- URE 11 is an end view of FIGURE 10.

FIGURE 12 is a plan view of the arrangement of FIG- URE 10 enclosed in a set of helically preformed armor rods, applied as shown in FIGURE 3.

FIGURE 13 is a side elevational view of the device shown in FIGURE 12, while FIGURE 14 is a sectional view taken along line 14-14 of FIGURE 13.

FIGURES 15 and 16 are side elevational and end views, respectively, of a fixture appurtenant to the present invention, shown in open position to engage a conductor; while FIGURE 17 shows the device of FIGURES 15 and 16 in closed relationship upon a conductor.

FIGURES l8 and 19 show the operation of enclosing the conductor and fitting of FIGURE 17 by a set of helically preformed armor rods.

FIGURES 20 and 21 are modifications of the invention especially adapted to dampen vibrations of suspended lines, the former figure being a sectional view taken along line 2020 of FIGURE 21.

FIGURE 22 is a plan view of a type of vibration damper made in accordance with the present invention, and FIGURE 23 is a sectional view taken along line 23-23 of FIGURE 22.

In the drawings, in which like characters of reference relate to corresponding parts throughout, helically preformed reinforcements are composed of a plurality of helically preformed elements 10, as shown in FIGURES 1 and 2. These may be of any suitable cross-sectional shape, this usually being either flat, as shown in my prior patent, above referred to, or round, as is shown in my pending applications, and as has been adopted herein for purposes of illustration.

A set of preformed armor rods is usually regarded as that number which, when assembled upon a conductor or other line-body of association, will completely enclose the same, or substantially so. As shown in FIGURE 3, a set of armor rods is divided into two groups, A and B, and these are arranged on opposite sides of a conductor or core C and twisted into position on the latter, commencing as shown in this figure adjacent the centers of the rods and continuing by turning the groups of rods in opposite directions to enclose the core C by a set 12 of preformed 3 armor rods as shown in FIGURE 4. The operation when complete is shown in FIGURES 5 and 6, in which the rods are all in place On the core C to constitute a tube of armoring 12 thereupon.

Since the internal diameter of the helices 10 is slightly less than the external diameter of the core C, the rods 16 individually, and the tube of rods 12 collectively, tightly embrace the core C and resist axial displacement mong the line. Also, the preformation and stiffness of the preformed stock is such as to resist unwinding, and to render the application of holding clamps or other tying means for retaining the armor in place entirely superfluous. Thus, projecting edges, corners, etc., usually associated with such attachments are eliminated, and electrical losses, as corona discharges, are minimized or precluded.

It has been found that the preformed rods 10 are as effective to hold other coaxial elements in place against a core or conductor as they are of retaining themselves thereon. This has given rise to the application of the devices shown in the ensuing figures of the drawings which are merely symbolic of means and methods for easily and inexpensively providing hanger brackets, vibration dampers, and various forms of taps and connectors to suspended transmission lines, and similar constructions.

Thus, in FIGURES 7 to 13, inclusive, there is illustrated one form of hanger bracket which, when used in conjunction with helically-preformed armor rods, constitutes one such attachment made in accordance with the present invention. In FIGURES 7 to 11, there is shown a hollow cylindrical member 14 which is divided along a plane of its central axis as at 16 to define a pair of complementary half-cylinders 18 and 20, respectively. The part 18 is provided with an autogenously connected central fin 22 which has an opening 24 for engagement with a supporting member (not shown). The fin is biased with respect to the longitudinal axis of the member 14 so as to extend along its base lines of attachment to the member at an angle which agrees, or nearly agrees, with the pitch angle of a set of armor rods 12, as shown in FIGURE 12. The bore 26 of the member 14 is of a size to receive a conductor or core C in such a way as to permit the contiguous edges 16 of the parts 18 and 20 to come into engagement, or substantially so, when in position. The member 14 is separated into its component parts 18 and 20, and these are positioned oppositely with respect to a core C, as shown in FIGURE 9, and closed thereupon, as shown in FIGURES 10 and 11. A set of armor rods 12 of a length considerably greater than that of the member 14 is applied as previously described so as to be substantially centered with respect to the member 14. When finally applied, as is represented in FIGURE 12, the armor rods embrace the member 14 and enclose it upon the conductor, and extend along the latter in each direction for at least a few pitch lengths to each side of the member 14, where the rods bear against the conductor in tightly embracing relation. 1 The fin 22 is accommodated between'adjacent armor rods without undue distortion, and the ends of the member 14 are chamfered, as at 28, to prevent abrupt changes in the diameters to which the armor rods must be accommodated. The slight distortion to which the armor rods are subjected in adapting themselves to the larger diameter of the member 14 tends to increase the spacing between the rods at this point, as is better seen in FIGURE 19, and alters the pitch somewhat, which exerts a crowding action and a tensile force upon the rods at the points where they are returned from the member 14 to the normal diameter of the conductor or core C to each side of the latter, and this appreciably increases the gripping effect on the core, and correspondingly strengthens the frictionalbond therebetween. This principle will be found to apply throughout the several modifications of the invention as are described herein.

A variant of the foregoing types of hangers is shown in FIGURES 15 to 19, inclusive. Here a set of armor rods 12 is applied to enclosea length of conductor C including a bump or protuberance adjacent the middle of the assembly, as finally appears in FIGURE 19. The bump or protuberance is preferably an elliptical solid 40 of wood, plastic, metal, or any other suitable material. Actually, it can be formed by casting a lump of low-melting metal upon the core in a proper mold, or it can be made from servings of twine, wire or tape. However, whereas these could be considered as suitable in cases of emergency, they are not the most convenient forms, which preferably conform to the general construction, shown in FIG- URES 15, 16, and 17. This comprises a chamfered cylinder or elliptical solid 4% having a bore 42 for accommodating the conductor or core C. The member 40 is split longitudinally into halves 44 and 46 for easy assemblage upon and around the core. When placed as shown in these figures, especially FIGURE 17, helical armor rods 10 are served along the conductor or core C, up and around the member 40, and down to and along the core again, as is shown in FIGURES 18 and 19. This provides a cable C with an armored portion having a bump or protuberance in its middle.

In some of the embodiments, especially in taps just described, and wherever electrical union is important, the members 14 and 49, Whatever their form, should have a central bore of a shape and size so as to permit their being drawn into tight engagement upon the underlying core C. This may mean that, when these parts are loosely assembled in the first instance, the adjacent edges of the component halves may not quite meet, but are forced to do so by the coaction of the forces arising from the armor rods being forced to assume a diameter larger than that to which they are preformed, and by the wedging action of the sockets as they are forcefully drawn toward each other upon the armored bump. This assures maximum area of intimate contact between the parts and assumes the best joint from the standpoint of electrical conductive properties.

In the case of FIGURES 20 and 21, however, this tight fit is not contemplated, nor, indeed, is it desirable. In this construction, the protuberating member 80 is designed with an oversize bore 82 with respect to the cable C, say, for example, in the order of a tenth of an inch (0.10"). Furthermore, the outer circumference of this member is enlarged considerably, and grooved helically to a lesser effective diameter for the accommodation of the helical armor rods therein without deformation beyond their elastic limit, and in a manner to conform to the pitch angle thereof. Grooves 84 accommodate the armor rods 10 and define the lands 86 which radiate between them. The armor rods 10, as in'previously explained examples, extend axially of the cable C for a considerable distance at each side of the member 80. This provides an ideal vibration damper for suspended cable such as overhead transmission lines. The armor rods lock the member 80 axial- 1y of the line, but the member itself is loose thereupon, and is thus free to move against the resilience of the rods both radially and circumferentially thereof, the circumferential components reflecting the torque effort expended by the preformed helical armor rods moving in response to vibrational impulses of the line C. The lands 86 increase the inertia of the member 80 by adding weight and dynamic balance to the assembly, thus enlarging upon the forces eifective to move it and enhancing its vibrational absorption powers as a damper.

A modified form of vibration damper is illustrated in FIGURES 22 and 23. Here the member 80, otherwise the same as that just described, is provided with a pair of radial extensions 88 of diametrically opposed lands 86 of equal length which are provided with weights 89 at their extremities. These increase the inertia effect of the damper in a well-known manner, especially as to the components of torque which arise from the working of the helical armor rods 1% under conditions of rising and falling tension along the line C, and its flexing during vibration. The extensions 88 serveadditionally as wind vanes which sneavoe are canted, propeller fashion, to exert torque through the rods 19 upon the line C in a manner tending to tighten and bind the rods 10 thereto. Thus, in conditions of heaviest Wind, which are also conditions of severest vibration, a damping force is introduced to the line that is proportional to the forces of wind acting upon it, and an eflicicnt damper is thus realized.

Although most of these exam l s have contemplated Whole sets of armor rods, and, indeed, whereas this is the preferred number, still any number of armor rods less than this, down to and including one, can be use as means for locking protuberating means, hangers and taps to such lines. Also, such instrumentalities as have been shown to comprise split half-cylinders, etc, as in FIGURES 7 and 15, among others, only the desired half of such dcvices need actually be employed, since they will be as effectively held against the line by helical armor rods as the wholly assembled parts. Furthermore, the holding power of the helices on the lines may be enhanced by the interposition of grit or other frictiongenerating medium. Furthermore, the protuberating means 4%, may be coated with abrasive grit, or serrated inside and out to increase its gripping of the line and retention of the rods. The interior surfaces of any of the sockets shown herein can be similarly treated.

There is no intention to limit this invention as to numer, placement and size of protuberating means. These obvious modifications are believed to speak for themselves, and require no further discussion beyond the statement that the invention, as claimed, is not so limited.

1 claim:

1. An accessory for suspended lines comprising, in combination, a protuberating means coaxially disposed about the line, a plurality of helically-preformed reinforcements s rronnding said protuberating means and the line for a distance at each end of said means so as firmly to lock the latter axially of the line; said protuberating means having an internal bore for accommodating said line that is larger in diameter than said line so as to be free for limited radial and circumferential movements with respect to the line against the natural resilience of said reinforcements.

2. The invention of claim 1, in which said protuberating means has helically-conforming passages for accommodation of the reinforcing elements, so that portions of its mass extend radially outward between the parting of the latter in substantially symmetrical relation to the line of association.

3. A vibration damper for suspended lines comprising, in combination, a protuberating means coaxially disposed about the line having an internal bore for the accommodation of the latter that is oversize with respect to the outside diameter of the line, a plurality of helically preformed reinforcements enclosing said means and extending 6 along the line at each end thereof, a pair of diametrically opposed vanes projecting from said protuberating means at an angle agreeing with the natural parting of said reinforcements, said vanes adapted to exert torque upon said protuberating means in response to conditions of wind impressed thereupon.

4. A vibration damper for suspended lines comprising a hub-like member having an internal bore Within which the line is accommodated in substantially coaxial relation therewith, vanes projecting from said member, helical armor rods securing said member to the line, said vanes extending through the natural parting of said helical rods and being canted to agree therewith, said damper being characterized by the fact that the vanes are adapted to apply torque to the member, and through it, to the armor rods to tighten their grip upon the line in response to conditions or" Wind, thereby to vary the damping effect as the vibrational influences vary.

5. The method of damping vibrations in a suspended conductor which includes embracing said conductor with helically-pretormed armor rods, and aoplying torque to said rods so as to vary their grin upon the conductor proportionally and in response to variations in the forces tending to vibrate said conductor.

lleter'ences Cited in the file of this patent UNITED STATES PATENTS 440,582 Bahlsen Nov. 11, 1890 1,061,252 Matricardi 6, 1913 1,155,460 Barlraur Oct. 5, 1915 1,996,782 Zapf 1933 1,968,888 Hillebrand Aug. '7, 1934 2,016,856 Fiege Oct. 8, 1935 2,172,810 Sherman 2,275,019 Peterson Mar. 3,

2,283,042 Burke May 12, 1942 2,315,015 Roberts vi'ar. 10, 1943 2,374,823 Leib et al. May 1, 1945 2,587,521 Peterson Feb. 26, 1952 2,679,690 Farr May 25, 1954 2,688,047 Maelntyre Aug. 31, 1954- 2,722,393 Peterson Nov. 1, 1955 2,777,895 Bergan Jan. 15, 1957 2,901,820 Clarin Sept. 1, 1959 2,967,812 Sorfiaten Oct. 6, 1959 2,959,632 Peterson Nov. 8, 1960 FOREIGN PATENTS 118,501 Great Britain Sept. 5, 1918 467,781 Great Britain June 23, 1937 591,592 Germany Jan. 24, 1934 432,821 France Oct. 12, 1911 864,361 France Jan. 13, 1941 

3. A VIBRATION DAMPER FOR SUSPENDED LINES COMPRISING, IN COMBINATION, A PROTUBERATING MEANS COAXIALLY DISPOSED ABOUT THE LINE HAVING AN INTERNAL BORE FOR THE ACCOMMODATION OF THE LATTER THAT IS OVERSIZED WITH RESPECT TO THE OUTSIDE DIAMETER OF THE LINE, A PLURALITY OF HELICALLY-PREFORMED REINFORCEMENTS ENCLOSING SAID MEANS AND EXTENDING ALONG THE LINE AT EACH END THEREOF, A PAIR OF DIAMETRICALLY OPPOSED VANES PROJECTING FROM SAID PROTUBERATING MEANS AT AN ANGLE AGREEING WITH THE NATURAL PARTING OF SAID REIN- 